Whisker resistant tin coatings and baths and methods for making such coatings
First Claim
Patent Images
1. A method for inhibiting tin whisker growth on a substrate material having a tin containing coating, said method comprising:
- preparing a tin coating solution containing a metal salt selected from the group consisting of palladium salts, silver salts, nickel salts, iron salts, cadmium salts, platinum salts, gold salts, indium salts, ruthenium salts, and cobalt salts; and
said preparing step comprising providing an initial tin containing solution and adding said metal salt to said initial solution in a concentration above the saturation point of the initial solution to form a metal salt saturated solution; and
applying said tin coating solution to said substrate material.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to an addition to tin coating solutions for inhibiting the growth of tin whiskers. The addition comprises a concentration of a metal salt selected from the group consisting of palladium salt, silver salt, nickel salt, iron salt, cadmium salt, platinum salt, gold salt, indium salt, ruthenium salt and cobalt salt. In a preferred embodiment, the metal salt addition is either a palladium salt such as palladium chloride or a silver salt such as silver sulfate.
83 Citations
18 Claims
-
1. A method for inhibiting tin whisker growth on a substrate material having a tin containing coating, said method comprising:
-
preparing a tin coating solution containing a metal salt selected from the group consisting of palladium salts, silver salts, nickel salts, iron salts, cadmium salts, platinum salts, gold salts, indium salts, ruthenium salts, and cobalt salts; and said preparing step comprising providing an initial tin containing solution and adding said metal salt to said initial solution in a concentration above the saturation point of the initial solution to form a metal salt saturated solution; and applying said tin coating solution to said substrate material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
- 12. A tin coating solution for imparting tin whisker formation resistance to a substrate material coated with a tin containing material, said solution comprising a tin containing solution having a concentration of a palladium salt, the palladium being present in an amount greater than about 50 ppm.
-
14. A composite structure for use in electrical and electronic applications comprising:
-
a metal or metal alloy substrate; a whisker resistant tin coating on at least one surface of said substrate, said tin coating consisting essentially of from about 0.1 w/o to about 20 w/o palladium for inhibiting tin whisker growth and the balance essentially tin; and said tin coating having an essentially smooth surface and a relatively fine grain structure of less than about 1 micron with said substrate being formed from copper or a copper base alloy.
-
-
15. A composite structure for use in electrical and electronic applications comprising:
-
a metal or metal alloy substrate; and a whisker resistant tin coating on at least one surface of said substrate, said tin coating consisting of from about 0.1 w/o to about 20 w/o palladium for inhibiting tin whisker growth and the balance essentially tin. - View Dependent Claims (16, 17, 18)
-
Specification